Turboman
Mab An Gov
Definitely worth investigation. Hard for me to say exactly how bad the failure is without seeing the vehicle.
Maybe the idler was the cause of the belt tracking across, the stud may have been cross threaded hence the hole now being stripped. From the pics that doesn't look like a helicoiled repair but i'd imagine it could be fixed with one. Probably have to be removed to be done properly
Turboman
Mab An Gov
I hadn't realised there were pics, connection is fairly slow here.
As you say, stripped threads are fairly common on those.
jamesmartin
Well-Known Member
if idler was loose that would do it, a helicoil or recoil would be the fix too
dag019
Well-Known Member
I think it has already had that done and it has stripped again as the seperate threaded section shown in the picture of the stud is not aluminium or the threads of the stud. If it has already had a failed helicoil repair can it still be repaired a second time.
I will have to invest in a helicoil set.
jamesmartin
Well-Known Member
if its a failed helicoil youll need some other method of repair,unless the helicoil tap provides a good new thread for the coil to sit in
dag019
Well-Known Member
Cheers I will check the new one before I got it.
dag019
Well-Known Member
Any suggestions? Guessing you can’t double them up.
jamesmartin
Well-Known Member
1.5
Kwakerman
Well-Known Member
If you can't get the helical to work then you may be able to get a stepped stud where there is a 12mm thread at one end that then necks does to 10mm for the idler. Obviously that would mean drilling and tapping the case out to M12 so you would need to check there is sufficient material to let you do that.
), obviously you would need descent spec material or possibly have one custom made?
dag019
Well-Known Member
Many thanks.
I had already thought of that, There is plenty of metal to increase to an m12 however finsing and m12 to m10 reducing stud appears to be very difficult. Other than an obscure toyota part which I cannot find for sale they do not seem to exists so may need to be custom
dag019
Well-Known Member
dag019
Well-Known Member
I have some left over high tensile 12mm studding that I used to make a puller for series chassis spring bushes, and I have m10 dies. I will see how easy it is to turn it down enough for the die to fit using the pillar drill and some emery paper. If that works I will then invest in some m12 taps to re-thread the hole and hope it all goes together square.
Kwakerman
Well-Known Member
If you do end up going that way then it may be worth making two, try fitting one in a lump of scrap aluminium, use your old idler and assemble it as would be on the engine. Try torque loading it to the. correct value to prove it works and then start over-torquing it to see at what torque it fails at, if it is 2 or 3 times higher (or more) than the correct torque then you should be ok. If it is only a little bit over the correct torque then it may be worth a rethink?
